OLED Display Border Reduction via Passivation Layer Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light-emitting diode displays face challenges with increased inactive border areas due to dam structures for encapsulation and stress-induced damage from bending, which affects display reliability and visibility.
Innovation Solution
The implementation of a substrate with conductive routing structures, encapsulation layers, and a passivation layer to reduce the inactive border area and alleviate stress through the use of inorganic and organic layers, along with a TFT passivation layer to protect against edge corrosion and align the neutral stress plane with metal traces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dam structures are formed to contain encapsulation material, then moisture protection is improved, but inactive border area increases
Solution Approach 1:
The patent extracts the dam structure from the traditional encapsulation system and replaces it with a passivation layer that is integrated into the substrate. This eliminates the need for separate dam structures while maintaining encapsulation integrity, thereby reducing the inactive border area without compromising moisture protection.
Solution Approach 2:
The passivation layer is merged with the substrate structure, combining the functions of encapsulation containment and stress management into a single integrated layer. This integration eliminates the need for separate dam structures and reduces the overall border area while maintaining protective functions.
2Ease of operation
If display is bent to hide inactive components, then visibility is improved, but stress-induced damage increases
Solution Approach 1:
The patent changes the mechanical parameters of the encapsulation system by using a passivation layer with specific stress characteristics that can accommodate bending. This layer is designed to manage stress distribution, allowing the display to be bent for better visibility while preventing stress-induced damage to metal traces and other components.
Solution Approach 2:
The passivation layer is applied beforehand to the substrate, creating a protective buffer that cushions against stress during bending operations. This pre-applied layer prevents stress concentration and damage to underlying metal traces before the bending occurs.
3Reliability
If passivation layer covers conductive routing structure, then edge corrosion is prevented, but manufacturing complexity increases
Solution Approach 1:
The passivation layer is merged with the existing substrate fabrication process, combining corrosion protection with the base substrate manufacturing. This integration ensures that the passivation layer is applied as part of the standard manufacturing sequence, preventing edge corrosion without significantly increasing overall manufacturing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration minimizes the inactive border area, enhances moisture protection, and reduces stress on metal traces, thereby improving display reliability and mechanical robustness while maintaining image quality.
Implementation Method 1
encapsulation layers formed over the active area of the display... The encapsulation layers includes a first inorganic layer, a second inorganic layer, and an organic layer interposed between the first and second inorganic layers
Implementation Method 2
a passivation layer that is formed on the conductive routing structure and below the encapsulation layers. The passivation layer may cover an outer edge of the conductive routing structure and may also cover lateral edges of the conductive routing structure to prevent edge corrosion during an anode etch
Implementation Method 3
a dam structure that contains the encapsulation layers within the display and that is formed directly over the conductive routing structure
Implementation Method 4
Thin-film transistor circuitry may be used to form pixel circuits that control the current applied through the light-emitting diode of each pixel
Implementation Method 5
When current is passed between the anode and the cathode through the emissive material, the light-emitting diode will emit light
Data Source
AI summary
A display having thin-film transistor (TFT) structures may be used to display images within an active area of the display, which is surrounded by an inactive border area. In order to reduce the inactive area, a TFT passivation layer may be used to help protect conductive routing lines at the outer edge of the border so that encapsulation layers need not be formed all the way to the edge. At least some of the conductive routing lines in the inactive area may be stacked or coupled in parallel to help reduce border width. The TFT passivation layer may also cover the lateral edges of the routing lines to help prevent corrosion during an anode etch. The encapsulation layers may also be formed in a bent portion of the display substrate to help adjust the neutral stress plane such that metal traces formed in the bent portion do not crack.